SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb9468a51b174fe3e3191a73658de34dcdd8bf5c207b2f8a1268d9abe51eb7be' 
  AND token = '3O52eK0ykKWQExUq5SNkdpKBsMSq8NQD2mDtbN6FuhQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}